Researchers have been looking into the opportunities and possible drawbacks of exploiting small, so-called ‘building-augmented’ wind turbines (BAWT) in Norway.
Small-scale wind turbine systems have the potential to make an important contribution to electricity generation in cities and other built-up areas. But what is the best way of exploiting wind energy in such areas?
Research scientists at SINTEF have been reviewing state-of-the-art technologies and have studied projects elsewhere in the world where wind turbines have been installed both on and in buildings. They have also carried out wind energy simulations, and building owners have been interviewed to survey attitudes regarding the possible installation of BAWT systems.
Placement and design will decide
Not surprisingly, those interviewed reported that turbine placement, size and design will be crucial in determining whether it will be profitable to install turbines in and on buildings. The topography of the area in question and possible wind tunnel effects are of major significance.
“Installing a wind turbine in a built-up area is entirely different from a hilltop location”, says Matthias Haase, a SINTEF researcher and author of the report. “Among other things, we have to consider a phenomenon called ‘wind shadow’ caused by surrounding buildings. This can be exploited, but it can also represent an obstacle to such projects. In general, there is less wind in built-up areas than in upland onshore regions or at sea. However, it is also possible to design a building so that it can accelerate local wind speeds. It is in fact possible to double wind velocities using the properties of the construction. In such situations you have to remember is that the wind power effect will in fact increase by as much as eight times”, he says.
In other words, it is fully possible to use this effect as a supplementary source of electricity. However, this field of research is in its early stages, and more know-how is needed. This is why researchers have already started planning a new project with the aim of obtaining more information about both wind conditions in cities, and small-scale, construction-adapted, wind turbine systems.
Looking for partners
Haase is on the lookout for partners who might be willing to fund the project. “Building owners, consultants, wind turbine manufacturers, installation contractors and other research institutes that want to participate or find out more about the project are more than welcome to contact me”, he says.
The results of the surveys are presented in the report Building-augmented wind turbines – BAWT and is currently being funded by the Norwegian bank Husbanken.